1. Field of Invention
This invention relates to an electrical connector.
2. Description of Related Art
A solar panel for use in a solar-energy power generation system is constructed of a plurality of modules connected one with another in series. A specific connector is used for an electric connection of the modules.
A known connector of this kind and its defects will now be described. As shown in FIG. 7, a single pole connector of this kind is constructed of a plug-side connector member C1 having a cylindrical housing 1 accommodating a plug terminal 2 which is a male terminal, and a socket-side connector member C2 having a cylindrical housing 3 accommodating a socket terminal 4 which is a female terminal.
A female fitting part 5 is provided at the front side of the housing 1 of the connector member C1, and a hollow sleeve-shaped male fitting part 6 is provided at the front side of the housing 3 of the connector member C2. As shown in FIG. 8, the plug terminal 2 and the socket terminal 4 are electrically connected with each other by fitting the male fitting part 6 into the female fitting part 5. Reference symbols W1 and W2 denote electric wires connected to the terminals and extending from the connector members C1 and C2, respectively.
An outer peripheral surface 6a of the male fitting part 6 is tapered towards its front end to facilitate insertion into the female fitting part 5.
In this known connector, the entire housing 1 of the plug-side connector member C1 including the female fitting part 5 and the entire housing 3 of the socket-side connector member C2 including the male fitting part 6 are formed of the same plastic material, such as PVC. PVC is comparatively hard and has a low degree of elasticity. Thus, the fitting parts 5 and 6 are hard, and have mechanical properties such that they are difficult to elastically deform.
Thus, it is difficult to obtain a mechanical effect such that the fitting resistance of the fitting parts 5 and 6 is low when they are being fitted together, while their removal or disconnection resistance is high after they are fitted together. That is to say, when a construction in which the male fitting part 6 is tight in the female fitting part 5 is adopted in consideration of stability of the connection it is hard to disconnect the male fitting part 6 from the female fitting part 5 and hard to fit the male fitting part 6 into the female fitting part 5. That is, the operability in connecting the connector members C1 and C2 is poor. When a construction in which the male fitting part 6 fits loosely in the female fitting part 5 is adopted in consideration of operability, it is easy to fit the parts together but also easy to disconnect them. That is, the plug terminal 2 and the socket terminal 4 are not stably connected with each other.
In this known connector, to prevent the fitting parts 5 and 6 from being disconnected, a locking rib 7 is formed on the outer peripheral surface of the male fitting part 6 and a locking groove 8 is formed on the inner peripheral surface of the female fitting part 5. The rib 7 and the groove 8 are engaged when the male fitting part 6 is fitted into the female fitting part 5.
The connector alternatively has a plurality of the locking ribs 7 and a plurality of the locking grooves 8 formed axially continuously in the shape of wave in section on the fitting parts 5 and 6.
The rib 7 and the groove 8 allow the male fitting part 6 to be loosely fitted into the female fitting part 5, but the locking rib 7 gives rise to a large fitting resistance. Thus, the fitting operation in this construction is not substantially different from the operation of press fitting the male fitting part 6 into the female fitting part 5 in a construction having neither locking rib 7 nor locking groove 8